The Latest Clojure Intertweets

We don’t get to report touching stories like this very often. Only tangentially related to clojure, this post is about an individual that decided to setup an Arduino store in West Africa, with the goal of getting more kids to interact and learn with electronics. The relationship with Clojure is that the author discovered Arduino while learning Clojure.

Data Science with Incanter and Clojure. There is a longer talk from the same author on the same topic.

Rich Hickey introduces this new ‘reducer’ library that decomplects (ha! I need to create a new blog called ‘decomplected’) the functionality of operating over a collection, only to rebuild the functionality back in a way that is both faster and more flexible. It also lets you skip paying the price of lazyness when you don’t need it. Finally, parallel execution when possible via Java’s fork/join and other goodies that only RH can think of. There is a related Hacker News thread.

Good to see ClojureScript being used on the server side. Clutch is a library to integrate with Apache CouchDB, a document database that provides a JavaScript engine to run queries. Clutch historically allowed writing queries in Clojure, support but you needed to add a JVM backend to CouchDB. Now you can write these queries in ClojureScript, and have them run natively on the JS backend. If you are curious, here is how CouchDB views look like.

Looks as if somebody is taking the pain of translating On Lisp to Clojure. By the way, you can get the original book as PDF for free.

Pretty good list, anyone has anything to add to it?

Clojure/Core is opening 3 slots for their fantastic training options, but this time you get to vote on what cities these sessions will take place. Cast your vote if you want it in your city!

Clojure-ns-browser is a nice way to explore Clojure and all the clojure libraries. It let’s you quickly jump from documentation, to sources and to usage examples. It is a Swing) application built with Seesaw

Ah, nice! A DSL for building Robot controlling software to control Lego Mindstorms and Arduino robots. Clojure already controls the server, the broswer, the client… now Robots. This is one seriosly cool DSL that generates code that can be understood by the cited platforms.

This article describes how to REPL-in to remotely running services where direct TCP connections are not possible, or more speficically, Heroku. Using drawbar, a HTTP transport for nRepl, you can open a REPL in an already runnign webapp. I have heard this technique has been used to fix satellites or other space ships. Probably not HTTP though.

As with hot peppers, red is not good news. And there is a lot of red in this picture. Contention!

This is a chart plotting the times Clojure appears in Hacker News (HN) posts, compared to Ruby, Python, Haskell and Scala. NHacker News is a place where entrepreneurs hang out. Two things seem clear from this graph: Clojure has taken quite a dive since mid-2010, and HN is talking less and less about programming in aggregate.

Rich Hickey keynoted at RailsConf with a plea for Simplicity. This talk has been quite popular amomgst Rails users, more so than the creator of Rails’s one. The slides are also available.

Neil Ford’s talk at JFokus 2012 (in Sweden) compelling its attendees to seriously consider Clojure.

Now this is one rant! Not everybody thinks that statelessness is a worthy goal. Some even think that striving for immutablility is evil. But some go even further and rant about how they think Functional Programming is “worse than crap.”

If you are writing an application that interacts with a social network you probably already know how hard it can be to test against the services provided by such social network. This library aids at creating automated integration tests against social networks.

This is not a library to generate Java bytecode. Instead, this turns bytecode into machine code for direct execution by the CPU. Crawl is a Clojure re-implementation of OpenJDK’s Graal.

Leveraging the new extensible reader literals in Clojure 1.4, Michael Fogus is implementing a reader literal for persistent queues. Check out the tests to figure out how it will look.

A call to action. We all want Clojure to have superb support for Windows, but only a few of us actually use Windows. Those of you who do, help?

Clojure 1.5 seems to be getting a new reduce library

This is a library that provides optimized tail calls to Clojure without having to call ‘recur’. It’s a source-to-source compiler and for now it only supports a small subset of Clojure. There is also a blog post with more details and the video of a recent presentation of this project.

An interesting discussion about Emacs Lisp, being based on mutability, makes things like equality very hard, and what are the possible solutions (none of them easy)

It’s easy to see where the writer of the article is going when the article starts with “Those who don’t understand the work of Rich Hickey are doomed to reinvent it, poorly”. And indeed, the author of clojure-py initially implemented functions differently than Clojure-jvm because Python has a way of making objects callable, which Java does’t provide. Well, it turns out that using IFn (which is used in Clojure-jvm) not only makes the compiler code simpler, it also makes it faster.

It used to be that in Clojure checked exceptions would be turned into RuntimeExceptions, and thus information was lost. This is not the case anymore in 1.4, and this article explains the implementation of sneaky-throws, used in 1.4 for this purpose.

The guys at ClojureWerkz have been producing new Clojure libraries at a high pace. You can now find them all in one single place.

This is the recording of a talk about making Tail Call Optimization performant enought in the Clojure/JVM. I couldn’t find the slides, and the video is not good enough to read the slides either, but the audio is good.

In this article Michael Fogus describes ClojureScripts compilation pipeline and how projects like Typed Clojure or binary compilation via Gambit fit in.

This is an awesome trick that has many uses, for example writing unit tests for a private function, or using private functions in macros. Both would not be possible if it wasn’t for this workaround the privacy of functions.

“With VMFest you can easily create and operate virtual machines, with emphasis on creating many clones of the same model VMs.” (Disclosure: I am the author). My –very well informed– sources tell me there are some cool new features about to come very soon.

Criterium is a benchmarking library for Clojure that avoids common pitfalls of software benchmarking: statistic soundness, warm-up periods, GC, etc.

A bunch of utilities and functions to make it easier to build powerful lein plugins

It looks very clojure-y, that’s for sure.

An interesting introduction to Clojure via a REPL session.

A bunch of Clojure-related projects got accepted for Google Summer of Code 2012 internships. Typed Clojure is one of them.

Rich Hickey speaking to a bunch of Rails developers… This is not going to end well.